Eye experts are worried that this dangerous fad is gaining popularity with preteens, especially after news reports of elementary school students in Japan who dared to test their ocular boundaries and caused multiple cases of pinkeye, otherwise known as conjunctivitis, the Daily Caller reported.

In one classroom of 12-year-olds, one third of students confessed to “worming” or being “wormed.” Officials only noticed something was up when some of the licked students showed up to school wearing eyepatches, ShanghaiList.com reported.

Not that you need an expert to tell you this is a bad idea, but here’s an expert to tell you this is a bad idea.

“Nothing good can come of this,” Granet warned HuffPost. “There are ridges on the tongue that can cause a corneal abrasion. And if a person hasn't washed out their mouth, they might put acid from citrus products or spices into the eye.”